1. Field of the Invention
This invention relates to a fingerprint image generating method in which a rising streamline patterned image on a fingerprint face of a fingertip is generated with a transferring technique and to a fingerprint image recording sheet practically which may be employed for the fingerprint image generating method.
2. Related Art
Fingerprints have been used as means for identifying a person, for example, in a field of the judicial office for identifying a suspect of a violation of traffic regulations or a criminal.
Conventionally, such fingerprints (fingerprint images) have been taken in the following manner that the fingerprint face of the fingertip is pressed against black seal ink so that the seal ink can adhere to the fingerprint face, and then pressed against a recording sheet. In other words, the seal ink adheres to a projecting portion (also referred as to a rising streamline) on the fingerprint face which has an uneven pattern so that the pattern of the projecting portion (rising streamline) can be transferred to the recording sheet, thus obtaining the rising streamline patterned image of the fingerprint.
In such a conventional method, the black seal ink remained on the fingertip after taking of fingerprint image needs wiping with a tissue paper or a cloth, but it is too difficult to wipe off because the seal ink filled in hollow portions of the uneven pattern on the fingerprint face can not be easily wiped away. Further, the tissue or the cloth needs preparing for wiping the seal ink and disposing thereof after end operation of wiping, resulting in an increase of incidental work.
On the other hand, the recording sheet to which the seal ink is transferred can not be piled up with other documents until the transferred ink dries or unless the wet and excess ink is removed by pressing with a blotter. For this reason, another problem arises that workability is lowered due to time needed for drying the seal ink after taking the fingerprint. Further, in this method, the image of the rising streamline becomes so bold as to lose the pattern thereof when the seal ink is used to excess for application to the fingerprint face, so that a clear fingerprint image can not be obtained.
Furthermore, when performing improper operation such as to press the fingerprint face excessively against the recording sheet or to slightly move the fingertip while pressing it against the recording sheet, the clear rising streamline patterned image of the fingerprint can not be clearly obtained as well. Thus, it is impossible to make a judgment on finely distinct fingerprint patterns not only in visual inspection, but also in a computing process after reading the fingerprint with a fingerprint reader.